If a user has multiple installation of phpbb or other software (non-PHP7 compatible) than the upgrade to 3.3 (and php7) will crush that other software. I'm not familiar with setting different php version per directoy and from a quick look at the setting in Cpanel I didn't find it... I assume that those with private servers might have it, but it is more "headache" for shared hosts and another technical "challenge"/Source for problems during upgrade.

Not really sure how other hosts are allowing for this, but I would imagine they probably have some way to do the same thing. If it's not the case that hosting providers are allowing for this then that might be another issue with the proposal since we can't guarantee other software, such as Coppermine, WordPress, Joomla!, Drupal, etc., will also work with PHP 7.

Anyway: what you suggest works, IF you host even supports both PHP 5.x and PHP 7.x. If not, a move from host A to host B is required in the process, something that complicates stuff.

I'll add one more complication to the mix, configuring the local testing environment to support multiple PHP versions.

My hosting provider does indeed support both PHP 5.x and PHP 7.0. So I've got the checked off.

However, as mentioned up topic, my local testbed (CentOS 7) only supports PHP 5.4.x. Through the selection of an outside repository (remi) I was able to add PHP 5.6 (or PHP 7) support. Since I've never had a requirement to run both versions, I'm on a learning curve to figure out how to update my testing environment so support multiple PHP versions so I can test my various forums (and WordPress and MediaWiki installs) without jumping through hoops. I'm a techie, so learning new stuff like this is education and fun, but I'm not sure every forum admin will take that viewpoint.

That shouldn't stop this discussion and moving forward on more current PHP version support, just add a data point about the life of forum admins.

Not really sure how other hosts are allowing for this, but I would imagine they probably have some way to do the same thing. If it's not the case that hosting providers are allowing for this then that might be another issue with the proposal since we can't guarantee other software, such as Coppermine, WordPress, Joomla!, Drupal, etc., will also work with PHP 7.

I have current experience with 4 different hosting companies in The Netherlands. 2 of them offer a simple switch trough the hosts' control panel, 1 offers it through a posting a request that's supposedly handled within 1 working day (not really ideal for such a procedure) and 1 doesn't offer PHP 7 at all.
Of course this is just a small sample of hosts and things will change within the coming year.

Above message may contain errors in grammar, spelling or wrongly chosen words. This is because I'm not a native speaker. My apologies in advance.

What are we keep sending stats info from the ACP if then we just jump ship with no good enough explanation?
Can we publish the stats data and see what it tells us?

Otherwise you're just going to have trolls and/or users who have no real understanding about the technology and therefore choosing an higher version just because sounds good. Already happened by the writing of this post.

Here's what should be published the same way about phpBB https://wordpress.org/about/stats/
If they upped the minimum requirement to PHP 7.0, do you think they would have the same user base?

Hey David, that's exactly what I was suggesting here... This would also make phpBB more transparent about how the data used and why.

I think some time has passed now and it has come to my attention that Symfony 3.4 will still support PHP 5.6. That will most likely be our targeted version of Symfony as it's a LTS release. Also, PHP 5.6 will most likely still be supported for the time phpBB 3.3 is released so I think it's a good idea to go with PHP 5.6 as minimum or the same as Symfony right now.